Publications

infectivity of anaplasma marginale after ingestion by potential insect vectors.	anaplasma marginale-infected erythrocytes retained viability and infectivity for at least 3 days after ingestion by hippelates pusio loew and up to 2 days after ingestion by species of tabanidae. the organism does not appear to have a developmental sequence in the insect vector.	1977	931144
influence of dexamethasone on the recrudescence of anaplasma marginale in splenectomized calves.	dexamethasone was administered at the dose rate of 0.2 mg/kg of body weight to 11 splenectomized anaplasma-carrier calves (groups 1 and 3) on monday, wednesday, and friday for 3 weeks. observations were made on these calves and on 7 nontreated, comparable calves (group 2) to determine the influence of treatment on carrier infections. dexamethasone treatment was associated in every instance with an exacerbation of the anaplasma parasitemia and a decrease in packed red cell volume. the episode of ...	1977	921027
cross reactivity between anaplasma marginale and two plasmodium species as demonstrated by passive hemagglutination.	two types of antigens were prepared from each of 3 partially purified preparations of anaplasma marginale, plasmodium lophurae, and p berghei. hemagglutination tests were conducted with homologous serums to detect antigenic relationships between these organisms. serums were also absorbed with both homologous and heterologous antigen preparations. cross reactivity between these organisms was observed.	1976	779540
serum levels of conglutinin, complement, and immunoconglutinin in cattle infected with anaplasma marginale.	sera from 10 splenectomized yearling cattle given massive doses of anaplasma marginale (peracute cases) were assayed for conglutinin and complement. sera from 5 nonsplenectomized yearling cattle given smaller doses (acute cases) were assayed for conglutinin, immunoconglutinin, and complement. in the peracute cases, conglutinating activity disappeared within 6 days after the cattle inoculated. in the acute cases, conglutining began to disappear at 3 weeks after inoculation and had disappeared at ...	1978	727576
epidemiology of cattle anaplasmosis in colombia: i. prevalence and distribution of agglutinating antibodies.	a survey to detect antibodies against anaplasma marginale, using the card test, was conducted on serum samples collected from cattle of cordoba department and north-eastern region of the department of antioquia in the republic of colombia. the samples were from native cattle of spanish descent (bos taurus), zebu (bos indicus) and various zebu-native crosses. the age range was between three and eight year olds. the results revealed that 90.3% of the samples were positive. all breeds showed a high ...	1978	705897
methods to improve the health of cattle in the tropics: conclusions and economic appraisal.	the results of the immune responses of immunised and chemoprophylactically treated calves to tick-borne (boophilus microplus) challenge indicate that the system of immunisation was effective in protecting cattle against anaplasma marginale, babesia argentina (bovis), and b. bigemina. however, chemoprophylaxis was effective only against babesia spp. but not against a. marginale. both methods showed a substantial advantage over no control system when using native cattle breeds in a zone endemic fo ...	1978	705891
elimination of the carrier state of bovine anaplasmosis with a long-acting oxytetracycline.	a long-acting formulation of oxytetracycline (l-200) was injected at a dose level of 20 mg/kg intramuscularly into 12 yearling cattle that had been experimentally inoculated with anaplasma marginale 64 days previously. four cattle were treated twice, 4 were treated 3 times, and 4 were treated 4 times. all injections were given once ever 7 days. previous work (unpublished) with this formulation has revealed prolonged blood values following a single injection. the blood (80 ml) of each calf was in ...	1978	677530
survey of the incidence of anaplasmosis among nigerian zebu trade cattle.	sera samples from 573 nigerian zebu trade cattle were evaluated by the rapid card agglutination test for antibodies to anaplasma marginale between may and july 1977. the results showed 34 per cent reactors as against 66 per cent negatives. the above results showed a significant level of exposure to the infection among the fulani cattle managed under a husbandry system in which there is no provision for tick control. the significance of this level of exposure to anaplasma marginale in relation to ...	1978	664019
methods to improve the health of cattle in the tropics: immunisation and chemoprophylaxis against haemoparasitic infections.	a study of methods to improve the health of native cattle in tropical areas of colombia showed an advantage using immunisation techniques against haemoparasitic infections in comparison with other control methods. the control of anaplasmosis and babesiosis by immunisation of cattle with fully virulent anaplasma marginale, babesia argentina and b. bigemina is feasible in tropical cattle when the postimmunisation reaction is controlled by appropriate drug therapy. chemoprophylaxis was found less e ...	1978	664017
serologic and hematologic response of rabbits to anaplasma marginale-infected bovine erythrocytes.	new zeland white rabbits inoculated with anaplasma marginale-infected bovine erythrocytes produced specific humoral antibodies to this parasite. specific antibody production as measured by the card and complement-fixation (cf) tests was maximal in 7 to 21 days after inoculation; however, none of the rabbits became infected. geometric mean cf titers of rabbits inoculated with rbc from cattle with acute anaplasmosis were significantly higher (p less than 0.001) than those of rabbits given rbc from ...	1978	646203
fluorescein diacetate staining of anaplasma marginale as a possible measure of viability.	fluorescein diacetate viability-staining technique was applied to anaplasma marginale. marginal bodies took up the stain and became fluorescent. when infected red blood cells were incubated at 55 c, the number of fluorescent anaplasma decreased at a rate similar to the known loss of viability.	1978	629472
efficacy of attenuated anaplasma marginale vaccine under laboratory and field conditions in colombia.	four-month-old holstein-friesian calves were inoculated with 3 different doses (1, 2, and 3 ml) of attenuated anaplasma marginale vaccine. vaccinated calves showed mild anaplasma parasitemia, slight decrease in packed cell volume, low serologic conversion, and no clinical illness. an artificial challenge exposure of vaccinated and unvaccinated calves with virulent colombian a marginale showed that the vaccine provided protection against clinical signs of the disease, including parasitemia and an ...	1978	629456
resistance to anaplasmosis after elimination of latent anaplasma marginale infections.	ten 30-month-old cattle (group 2) were inoculated with anaplasma marginale 6 months after the latent a marginale infection was eliminated by oral chlortetracycline therapy. in addition, 4 cattle (group 1) with no record of infection and 4 cattle (group 3) of equivalent age previously vaccinated with a killed antigen were similarly inoculated. moderate to severe clinical signs of acute anaplasmosis occurred in the group 1 (previously uninfected) cattle, whereas only 1 of the chlortetracycline-tre ...	1977	557302
comparative efficacy of drugs in bovine anaplasmosis.	calves experimentally infected with anaplasma marginale were subjected to chemotherapeutic treatment in groups, each group receiving one drug only. observations were made on clinical signs, haematological changes, parasitaemias and levels of antibodies as measured by the complement fixation test. the most effective treatment was with imidocarb; other drugs which were apparently effective were steclin, terramycin and aureomycin in that order, while chloroquin diphosphate and camoquin gave little ...	1979	552672
[preparation and comparative testing of antigens for the immunodiagnosis of anaplasmosis in cattle].	three antigen types were produced by ultra-sound treatment of the initial material (anaplasma marginale theiler infected blood) and its subsequent sedimentional centrifugation from 10 000 to 100 000 g. their specificity and susceptibility to the reaction complement binding (rcb) and to the capillary agglutination (ca) serological tests was comparatively checked up. antigens a and b were very active in rcb, while antigen b--in the ca reaction. by these qualities they meet the requirements and are ...	1979	545841
electron microscope studies of anaplasma marginale in an aedes albopictus culture system.	anaplasma marginale was seen by electron microscopy within the cytoplasm of aedes albopictus cells in culture. anaplasma marginale was seen in free bovine rbc as well as in rbc phagocytized by ae albopictus cells. some a marginale organisms, both intracellular and extracellular, remained intact for as long as 60 days in culture, and anaplasma inclusion appendages were seen in free-lysed rbc and in lysed rbc phagocytized by ae albopictus cells. although some a marginale organisms had deteriorated ...	1979	525907
in vitro cultivation of anaplasma marginale: invasion of and development in noninfected erythrocytes.	ovine erythrocytes infected with attenuated anaplasma marginale organisms were cultured in a suspension of normal ovine erythrocytes and normal bovine erythrocytes for 42 days. in each system, the organism showed an initial period of rapid growth followed by a gradual decrease in the percentage of parasitized erythrocytes accompanied by cyclic peaks. the percentage of infection of ovine erythrocytes were not different when normal ovine or bovine erythrocytes were added to the cultures. in vitro ...	1979	525898
evaluation of the anaplasmosis rapid card agglutination test for detecting experimentally-infected elk.	anaplasma marginale was experimentally transmitted from cattle to elk to cattle. six intact adult elk (cervus canadensis canadensis) inoculated with freshly collected heparinized blood from cattle chronically infected with a. marginale became asymptomatic carriers. although the elk did not develop clinical or hematologic evidence of infection, they became seropositive by the serum(srca) and plasma rapid card agglutination (prca) tests. blood from the experimentally-infected elk produced disease ...	1979	501840
comparisons of the complement-fixation, indirect fluorescent antibody, and card agglutination tests for the diagnosis of bovine anaplasmosis.	results of complement-fixation (cf), indirect fluorescent antibody (ifa), and card agglutination (ct) tests were statistically compared, using 380 serum samples obtained from 140 cattle which were disease-free or naturally or experimentally infected with anaplasma marginale of colombian origin. the ifa test was significantly the most sensitive for detection of amimals infected with anaplasmosis (97%); the ct test and the cf test were less so (84% and 79%, respectively). however, the most efficie ...	1978	358874
detection of antibodies in trypanosome-infected cattle by means of a microplate enzyme-linked immunosorbent assay.	a micromodification of the enzyme-linked immunosorbent assay (elisa) was evaluated for its potential application in the immunodiagonsis of bovine trypanosomiasis. serum samples from infected and non-infected zebu cattle and samples from friesian cattle with experimental infections were exmained for the presence of trypanosomal antibodies. there were significant differences between the microelisa values obtained with samples from infected and non-infected cattle. during the course of infection mi ...	1977	333677
exit of anaplasma marginale from bovine red blood cells.	incubation of anaplasma marginale-infected bovine red blood cells in a flow culture system resulted in a decrease of observable marginal bodies. the decrease was twice the degree of hemolysis, indicating that marginal bodies may leave red blood cells without concomitant lysis of the host cell.	1975	237446
changes in serum concentration of phagocytosis-stimulating factor in experimentally induced bovine anaplasmosis: preliminary findings.	to determine whether correlation exists between serum concentration of phagocytosis-stimulating factor (psf) and in vivo phagocytic activity, 2 splenectomized steers were inoculated with anaplasma marginale, and their serum psf concentrations were monitored. at the time of the anemic crisis, serum psf concentrations were elevated five to tenfold.	1976	58572